1. Field of the Invention
This invention relates to a water purification system and a method for purifying water for drinking. In particular, this invention relates to a water purification system and method in which a large quantity of bathing-quality water is purified to potable water for use by entire communities.
2. The Prior Art
Contaminated drinking water is a large problem in developing countries and leads to widespread infection and disease. In nations where water is scarce, purified drinking water is often too expensive for the average citizen to buy. In addition, the quantities of purified drinking water available are limited. This situation also exists temporarily in areas that have been hit by natural disasters such as hurricanes, earthquakes, floods, etc.
In disaster areas, water is often brought to the disaster site in large containers. This method is extremely expensive and very cumbersome.
There have been many attempts to develop water purification systems capable of treating large quantities of water for drinking. Some prior methods involve purifying the water via filtration and chemical disinfectants such as chlorine. However, chemical disinfectants can have harmful side effects as well, and some, such as chlorine, can lead to the formation of carcinogens.
One attempted solution to this problem is disclosed in U. S. Pat. No. 5,741,416, to Tempest, Jr. This patent discloses a water purification system having a filter, a means for oxidizing organic substances in the water, a disinfecting means and an antiviral means. a mechanism for coagulating colloidal particles, and a chemical disinfectant. Other water purification systems are disclosed in U.S. Pat. No. 5,728,305 to Hawkinson and U.S. Pat. No. 5,512,178 to Dempo.
While there are many systems that can convert contaminated water into potable water, many of these systems use harmful chemicals or are not easily transported to disaster sites. In addition, none of the prior art systems provide a method for the people needing the water to collect the water in a sanitary manner from the treatment system.
It is therefore an object of the present invention to provide a water purification system that converts contaminated water to potable water in an inexpensive and simple manner.
It is another object of the invention to provide a water purification system that does not add any potentially harmful chemicals to the water.
It is another object of the invention to provide a water purification system that has means for allowing the people in need of the water to carry the water away in a sanitary manner.
It is a further object of the present invention to provide a water purification system that can be easily transported to an area in need.
These and other objects of the invention are accomplished by a water purification system comprising a housing, a water inlet, filtering means for filtering sediment and particulate matter from the water, an inlet pump for keeping the water flowing through the housing at a predetermined pressure and a mixed bed multimedia unit for removing pollutants and controlling organic growth from the water. There is also an ultra-violet treatment means for subjecting the water in the system to ultraviolet radiation, carbon block filtration means for filtering the water of organic material, and at least one means for washing a water bottle dispensed within the housing and there is an ozone treatment following the UV treatment which effectively destroys any residual bacteria or organics. The filtered water is then pumped through a dispensing means to dispense the water into the washed bottles.
The filtering means is preferably comprised of a macrofiltration unit and a microfiltration unit. The macrofiltration unit is connected at the input of the water conduit, before the water is pumped through the inlet pump. The macrofiltration unit is essentially a strainer to remove sediment and particulate matter larger than 80 microns. Preferably, this unit is visible from the outside of the housing so that the filter can be observed for maintenance. A macrofiltration unit is necessary to protect pumps, valves and other components from damage, malfunctions and a shortened life.
The microfiltration unit is a cartridge filter and removes particulate matter and sediment as small as 10 microns and possibly as small as 0.35 microns. One microfilter may be used, or several may be placed in series. The inlet pump is necessary to keep the inlet water flowing at 60 psi. The inlet pump is preferably arranged between the macrofiltration unit and the microfiltration unit.
The mixed bed multimedia filter follows the microfiltration unit and is a cartridge containing granular activated carbon, quartz, and a granulated copper-zinc material. The quartz acts as a distribution media and the carbon removes organics, taste, odors and soluble particulates from the water. The copper-zinc material is used for its galvanic action to remove chlorine, heavy metals, bacteria, algae and fungi. A suitable copper-zinc material for the mixed-bed multimedia unit is sold by KDF, under the name KDF55. Both the microfiltration unit and the mixed-bed multimedia unit must be replaced when the pressure drop across the filter reaches a predetermined level.
The ultraviolet treatment unit follows the mixed-bed multimedia unit and comprises a UV bulb that emits intense ultraviolet light. The ultraviolet radiation destroys any microorganisms and bacteria that may be present in the water.
The ozone treatment follows the UV treatment and is created via a corona arc across an air stream. The ozone laden air is then injected via a spray nozzle into the water. Ozone removes organics and microorganisms in the water. It is a powerful oxidizer that imparts disinfectant treatment to the water. Ozone destroys bacteria and viruses, oxidizes heavy metals and eliminates unpleasant odors. Ozone converts back to oxygen after a few hours. If the water is to be consumed immediately after ozone treatment, the ozone must be removed from the water as it causes nausea in some people.
The water is dispensed from the housing with the aid of a dispensing pump to ensure constant pressure at the discharge dispenser heads. There are preferably several heads for dispensing the water within each housing.
The carbon block filtration unit comprises a carbon block filter cartridge that forces any remaining particulate and dissolved organic compounds to be retained as a final purification. This step also removes any residual ozone. This filtration unit is preferably arranged after the dispensing pump just prior to the dispensing heads.
Also connected to the dispensing pump is a parallel piping circuit that leads to one or more bottle washing stations. The bottle washing stations are set up to wash bottles with 1xe2x80x3 to 2.5xe2x80x3 diameter openings. There is a cleaning liquid spray nozzle that sprays a detergent upwards into an inverted bottle. The detergent then drains out of the bottle into a drain in the housing. The bottle is then rinsed with purified water, either manually, or with an automatic inverted nozzle as well. This washing action can be initiated automatically upon placing a bottle onto the nozzle, or it can be started with a push button. The washing cycle includes a wash, drain and rinse cycle that is accomplished in 10 to 30 seconds, at which time the bottle is removed from the washing station and is ready for filling with water at the dispensing station. The drain is sent to a sewer for post treatment to comply with local regulations.
There is preferably a back-up power generator within the housing and connected to the inlet pump, dispensing pump, UV treatment, ozone treatment and detergent mixer for supplying power during a power failure.
The system according to the present invention takes bathing grade water and purifies it into drinking water in a simple and economic manner. The system according to the present invention can supply safe drinking water to an entire village at low cost and with low maintenance. The system is easily transported via a trailer or helicopter to the desired location. There are preferably two bottle washing stations and four dispensing heads, so that several people can receive water at one time. The system is equipped to supply about 5,000-20,000 gallons of potable water per day, with the 5,000 gpd version able to supply the daily drinking water needs of about 2,000-3,000 people. Different inlet water compositions can be accommodated by changing the individual component design capacities to achieve the optimum quantities of purified water.